Traditional macro wireless networks such as code division multiple access (CDMA) networks include a number of base transceiver stations (BTSs), mobile switching centers (MSCs) and base station controllers (BSCs). The BTSs each cover a geographic region, or cell, of the wireless network and communicate with mobile telephones in the cell. The MSCs/BSCs provide switch and soft handoff functionality for the wireless network.
Micro wireless networks, such as wireless local access networks (WLANs), typically include a number of access points (similar to macro base stations) and several IP routing devices. The access points each cover a geographic region of the WLAN and communicate with mobile devices in the local network. The IP routing devices provide connectivity to an IP network, and manage the mobility of the micro devices within a micro network.
Mobile vendors offer dual mode phones capable of communicating with both macro and micro networks. Current proposals to provide service portability for such devices across the macro and micro networks include running Mobile IP applications on end devices, running Proxy Mobile IP applications on access points or other devices, treating the WLAN cells as disjoint cells with respect to the macro cells.